Display device for typewriters



T. J. wATsoN 2,310,482

DISPLAY DEVICE FOR TYPEWRITERS Filed Sept. 27, 1940 3 vSheets-Sheet l Feb. 9, '1943.

INVEVJ'QR. j ATTQRNEY'...

Feb. 9, 1943. T. J. wATsoN DISPLAY DEVICE FORl TYPEWRITERS smv Feb- 9 1943 I T. J. WATSON 2,310,482

DISILAY DVICE FOR TYPEWRITERS Filed Sept. 27, 1940 3 Sheets-Sheet 3 B Mw ATTORNEY.

Patented Feb. 9, 1943 DISPLAY DEVICE FOR TYPEWRITERS Thomas J. Watson, New York, N. Y., assignor to International Business Machines Corporation. New York, N. Y., a corporation o! New York Application September 27, 1940, Serial No. 358,572

17 Claims.

This invention relates to a. display device for stressing the ease of operation of the individual keys o1' a typewriter or other key-controlled machine.

The primary feature intended to be demonstrated by the instant invention is commonly referred to in the art as lightness of touch.

, To illustrate this feature most effectively, it is contemplated to provide for the operation of the typewriter keys by the action of light beams originating from a common light source mounted above the keyboard.

It is further contemplated to provide for mounting a photo-voltaic cell in the head of each key so that each cell, when acted upon by a light beam, effects control of circuits for operating the key in which it is mounted. The impression thus conveyed to an observer is that the' light beams are actually depressing the keys by the exertion of a very slight mechanical pressure. This illusion lends an` air of mystery to the display which attracts the observer and impresses on his mind the extremely light touch oi' the keys of the particular typewriter on display.

It is also within the contemplation of the invention to provide light means to illustrate the characters asthey are printed, and it is pro-- posed that the light means remain lighted until a predetermined number of such characters is printed.

According to the invention, a perforated metal tape is mounted for intermittent movement in front of a projector lamp. Between the tape and the lamp is a shutter which is operated in- `termittently from the same driving means as the tape. The operation is such that the shutter is held in front of the lamp while the tape is being advanced and is moved away from the lamp as the tape stops. When the shutter moves away, light passes through a perforation in the section of the tape immediately in front of the lamp. As this occurs, light is reflected by anl inclined mirror in such a manner as to fall on one of the typewriter keys. Upon receiving the light beam, a photoceil within the head of the key becomes active to generate a very small current, which current is amplified to energize akey solenoid and thus depress the key. A key selector is provided and has segments connected 'r to the individual key solenoids in a vpredetermined manner in accordance with the information which is to be printed. As the key selector rotates, it contacts the various segments in order (Cl. IS7-20).

A lamp selector, mechanically connected with the key selector to insure synchronous operation, serves to control completion of a lamp circuit each time a light beam falls on a key. A holding circuit is provided for maintaining the lamps lighted until a. predetermined number of characters has been printed, at which time the circuit is opened to darken the lamps.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a schematic view of apparatus showing the general relationship ofthe units.

Fig. 2 shows diagrammatically the elements for controlling the light beam for one typewriter key.

Fig. 3 shows a portion of the control tape.

Fig. 4 isa circuit diagram of the entire device.

Fig. 5 is a sectional view of the principal operating mechanism of the typewriter.

Fig. 6 is a plan view showing the principal parts of the drive mechanism.

The invention is shown in the drawings as applied to a power driven typewriter of a well known type, the principles of which are disclosed in Patents Nos. 1,777,055 and 1,873,512, although its use is not limited to such machines. In the illustrated machine, briey, depression of a character key 8 releases a latch 'i from a. cam 8 permitting a spring-pressed lever 9 to move the cam against a continuouslyrqtating motor-driven power roller IG. The cam is rotated by rictional contact with the power roller in a clockwise direction, as viewed in the drawings, to cause the rocking of the cam carrier member ii to depress a link i2. Depression of link i2 rocks a linkage i3 to propel the type bar I4 towards the platen I5, causing the type on the type bar to print on the sheet positioned on the platen.

The carriage return key 5 operates carriage return means such as disclosed in Patent No. 1,955,614. Depression of key 5 releases latch I'la from cam 8a to permit spring-pressed lever 9a to move the cam into engagement with power roller I0. It will be noted that cam 8a differs in shape from cam 8 in that it is a single rather than double lobecam. 'I'he reason for this is simply to permit cam 8a to turn one complete revolution upon engagement with the power roller rather than one-half revolution as does cam 8. Rotation of cam 8a in a counterclockwise direction by power roller l0 causes rocking of cam carrier member lla and depression of link I2a to effect a carriage return operation.

In this type oi machine, carriage return operations are accompanied byan automatic line spacing of the sheet positioned on the platen I5.

A robot mechanism, represented diagrammaticallir by rectangle in Fig. 1 contains a suitable drive motor M (Fig. 6) for driving a shaft 2I that carries three cams which operate control 5 way of wire 53. The micro-relay 52 is energized l.

contacts and which are designated CBI to 3. The cams are fixed to the shaft so as to rotate therewith and are shaped to control the time of opening and closing of their associated contacts to operate circuits which are described hereinafter. Shaft 2| is connected by gears 22 to a shaft 23. Shaft 23 in turn is 4geared to a vertical shaft 24 to which is fastened a cam 25 carrying a. pin 25a. The pin 25a engages with a Geneva gear 26 rotatably mounted on a supporting stub shaft 21. Integral with the Geneva gear 26 is a drive wheel 28 which engages with a metal tape T for feeding the tape intermittently in accordance with the movement of Geneva gear 26. Guide spools 29 take up the slack in the tape and support a portion of the tape directly in front of the projector lamp 38. A shutter 3l is provided between the tape and the lamp and is arranged to be moved back and forth by the cam 25 acting through connected linkage 32. 'I'he contour of cam 25 is such that it moves the shutter out of alignment with the lamp while the tape is not being advanced by the Geneva drive gear 26. At all other times the shutter remains in alignment with the projector lamp so as to intercept any light beams from the lamp which may pass through the tape. A'mirror 33 (Fig. 2) is provided and is Supported at an angle to reflect light beams from the projector lamp in the direction of the keys.

'I'he tape T comprises a plurality of sections which are successively presented at the projector lamp by the Geneva drive movement. A perforation may appear in any one of a number of predetermined locations in a section of the tape but only one perforation is allocated to a section since only one typewriter key is adapted for operation at a. time. The sections of the tape are made suiciently large to accommodate perforations in as many different positions as there are keys on the typewriter.

In the top of each typewriter key is embedded a tiny photocell which becomes active to generate a smal1 current when a light beam strikes upon the top of the key. 'Ihe circuitsvvwillgbe described later, it being sufficient for the present to state that a solenoid SO, located directly beneath the key contacted by the light beam, becomes energized to depress the key. Also connected with the drive motor 2| through a reduction gearing 31 and shaft 38 are two arms 39 and 48 which cooperate with the segments of disks 4I and 42, respectively. The arms are kept in exact synchronism by virtue of the fact that each is fixed to shaft 38. Thus, corresponding segprojector lamp 30 and this light beam is directed by mirror 33 upon one of the photocells 35, a live circuit is completed by the photocell through wire 5I to micro-relay coil 52, and returned by to close its contacts 52a to complete a circuit from wire 49, contacts 52a, resistances rl, r2, wire 54, contacts CB4, to wire 58. The potential drop across resistances rl, r2 causes an increase in potential of starter anode 55 of tube 58 with i' respect to the cathode 51, thereby causing current to flow through this tube to the anode 58 to complete` a circuit when contacts CB3 closeI through relay coil I as follows: wire 49, wire 58. contacts CB3 now closed, Wire 68, relay coil I, anode 58, cathode 51, wire 54, contacts CB4, and `wire 58. Energization of relay coil I ycloses its contacts IA. Assuming that switch 46 is closed to connect wires 41 and 48 to the AC line, when contacts CBI close, a circuit is completed from wire 41, contacts IA now closed,contacts CBI also now closed, selector arm 39, through4 one of the' segments of disk 4I, wire 43, solenoid SO, to wire 48. Energization of the solenoid SO causes depression of its associated key to print a character.

Energization of relay coil I also closes its contacts IB to complete, when contacts CB2 close, a circuit as follows: wire 43 wires 6I, 82, contacts CB2, wire 63, selector arm 48, through a segment of disk 42, through one of the coils 4P,

5P or 6P, contacts 4IB now closedwires 64, 85,

contacts CB4, to wire.58. Energization of relay coil 4P, for example, closes points 4A to provide,

a Vholding circuit from wire 49, wire 6I, coll 4H, -contacts4A now closed, wire 66, 54, 65, contacts CB4 to wire 50. 'I'his holding circuit is under control of contacts CB4. Energization of relays 4P and 4H, respectively, closes and holds contacts 4B, thereby vcompleting a circuit to light one of the lamps 10 as follows: wire 48, wire 44, contacts 4B now closed, lamp 18 connected thereto, and Wire 41.

The display panel comprises .a plurality of `lamps 10 arranged in rows as shown in Fig. 1. A predetermined message such as, for example, This is a light touch typewriter is printed on the inside of the panel, and the letters of the message are-normally invisible from the outside of the panel. However, by providing a lamp 18 ofachrlettf-'snaggessage is rendered visible letter by letter when theampsareiightedraaw circuits described above are completed through the lamp selector arm and the normal segments of disk 42.

After the lamps have been lighted to render the entire message visible, the lamp selector arm 40 contacts a special segment 42a to energize relay 2P over the following circuit: wires 49, 6I, 62, contacts CB2 now closed, wire 63, selector arm ments of their respective disks are contacted by 60 40, Segment 42a, Wire 51, coil 2P, wire 65, conthe arms 39 and 48 at the same time. Disk 4I and selector arm 39 serve to select the solenoids for energization, and disk 42 and arm 40 control the lighting of the lamps on the display panel. Shaft 38 also carries circuit breaker cam CB4.

The electrical circuits will now be described with reference to Fig. 4. There it will be noted that the closure of switch connects wires 49 y and to opposite terminals of the DC supply. This completes the following circuit to start the drive motor 2l: from wire 4 9, through wirer, drive motor 2l, wire 8l, normally closed switch 2A, wire 82, to wire 50. Then, when a hole in the tape is encountered by a light tacts CB4, and wire 58. Energization of coil 2P closes contacts 2BL to energize coil 2H by a circuit which is traceable from wire 49, wire 6 I wire 68, contacts 2BL now closed, coil 2H, wire 65, con- 5 tacts CB4, to wire 50. Contacts 2B,U are also closed to effect a circuit through relay coil 3, from wire 49, wires 6I, 68, contacts 2BU, coil 3, normally closed contacts 3B, resistances 1I, 12, to starter anode 13 of tube 14. This builds up the potential on the starter anode 13 which fires the tube, so that current passes through the tube from relay coil 3, plate 15, cathode 16, wire 65, contacts CB4, to wire 58. As soon as relay coil beam from the 3 is energized by the above circuit, contacts 3B operation of Said key by its individual operating.

are transferred so that the circuit is held through resistance ll.l Contacts 3A also close to complete a circuit through the drive motor asx follows: wire 49, wire 80, drive motor 2l, wire 8|, contacts 3A now closed, wire 82 and wire 50. The motor now causes arm lll tol be moved o segment 62a, thereby breaking the holding circuit for relay coils 2P and 3 and permitting contacts 2A to close and hold the motor circuit during the movement of arm 40 past the remaining segments of disk d2. The last segment on the disk is generally connected to the carriage return key solenoid so as to effect'a carriage return and line space when light passes through the last hole in the tape and falls on the carriage return key. Contacts CB open to darken lamps .l at this time.

The above described mechanism creates a time delay at the e'nd of each revolution of the selector arm Il@ as it contacts segment 42a. During this time delay, the moiorarid all the connected mechanism are stopped for a brief period.

,Then when relay 3 is picked up, the motor resumes its normal operation through contacts 3A and then through contacts 2A which close upon deenergization of relay 2P when arm 40 moves oi of segment 62a.

It has been found thatfor proper operation `light from lamp t3 in. accordance with the amount of stray light falling on the typewriter. Lamps 86 and 85 are connected across the AC line and lamp 33 is connected across the DC line in series with the resistor 86, as shown in Fig. 4.

The present application is directed to the light controlled key operating mechanism, while the .light controlled display panel is co'vered in my divisional application Serial No. 408,973, filed August 30, 1941.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the inven tion. It is the intention, therefore, to be limited only as indicated by the scope of the f ollowing claims.

What is claimed is:

1. In a display device, a machine comprising a plurality of manipulative members, a light source,

means. l

3. In a display device,` a machine comprisin a plurality of keys, illuminating means, means for controlling said illuminating means so as to direct concentrated beams of light on saidkeys in a predetermined order,I electrical means for operating the keys individually, and means including a device carried by each key and respon-l sive to the light beams as said beams are received by the keys for energizing the individual electrical means to operate the keys.

4. In a display device, a machine comprising a plurality of keys, illuminating means, means for regulatingl said illuminating means so as to direct concentrated beams of light on said keys in a predetermined sequence, electromagnetic means' for operating the keys individually, selecting means for selecting the individual electromag- 5. In a display device, a machine comprising a plurality of keys, a light source, means for controlling the direction of light from said source to cause light beams to fall on the keys in a predetermined sequence, electromagnetic means for operating the keys individually, a rotary distributor having segments connected to the electromagnetic means and a rotating arm contacting said segments in a predetermined order corresponding to and in synchronism with the direction of the light beams on the keys for preparing said electromagnetic means for operation, and means comprising light sensitive devices carried by said keys and rendered active by the light beams' as said beams are directed onthe keys to cause energization of the prepared electromagnetic means to operate the keys.

6. In a device of the character described, a

- keyboard comprising a plurality of keys, illumimeans for controlling the direction of light from said source to cause light beams to fall on the members in a. predetermined sequence, individual means for operating said members, and means comprising a, light responsive device mounted on each manipulative member-and rendered active by one of the light beams as saidlbeam falls on said member, to cause operation of the member by its individual operating means.

2. In a display device, a machine comprising a plurality of keys, .a light source, means for regulating said light source to cause light beams to fall on the keys in predetermined sequence, in' dividual means for operating said keys, and means comprising a light sensitive device carried by each key and rendered active by one of the light beams as said beami'alls'on the key to causey nating means mounted over said keyboard, means for Vcontrollingthe light from said illuminating means to cause concentrated beams of said light hto fall on the vkeys in a predetermined sequence,

individual operating means for depressing said keys, and means comprising a photo-'voltaic cell carried within the `head of each key and rendered active by one of the light beams as said beam contacts said key to cause depression of the said key by its individual Ioperating means.

Y'7. A display device comprising, in combination, a keyboard having a plurality of keys, a light source mounted over said keyboard, means for directing beams of light from said source on said keys'in a predetermined sequence, an electromagnet for each key, and means comprising a photocell mounted in the head of each key which is responsive `to a light beam as saidl perforations on said tape, individual means for operating said members, and means comprising a photocell carried by each of said members and eifective when light from the light source is directed on the related member to cause operation of the latter member by its individual operating means.

9. In a display device, a machine comprisinga plurality of manipulative members, illuminating means, a perforated record material insertible between the illuminatingmeans and the keys so as to prevent light from said illuminating means from contacting said keys except through the perforations disposed in predetermined locations in said material, means for feeding said material so that the perforations are presented one at a time in front of the illuminating means, a photocell carried by each key, light control devices for causing the `light passing through each perforation to fal1 on a predetermined different one of said keys according to the location of said perforation on the tape, to operate the photocell carried by said key, individual operating means for each key, andmeans controlled by said photocells to energize the related key operating means.

10. In a device of the character described, a`

forations therein, means for feeding the tapev so as to bring the perforations successively in front of said light source and between the source and the keys, the tape preventing light from the source from reaching the keys except by Way of the perforations therein, and light directing means for directing light passing through a perforation to a predetermined one of said keys in accordance with said perforation to operate the photocell carried thereby to eiect energlzation of the related magnet to operate said key.

11. In a display device, a typewriter having a plurality of keys, a light source, a control tape carrying character-representing perforations thereon, means for feeding said tape past said source to cause said perforations to be brought successively in front of the said source, whereby light beams pass through said perforations to predetermined different keys of the typewriter in accordance with the location of said perforations,

`individual operating means for said keys, and

Y the photocells in the heads oi the said keys.

12. In a display device, a machine comprising a plurality of keys, a ligh't source, a control tape comprising a plurality ci?v sections bearing perforations representing charactersthereon, intermittent means for feeding said tape past the light source so as to bring one section of the tape at a time to a point of rest in line with said source, a shutter, means for controlling the shutter so as to intercept the light from the light source while the tape is being fed by the feeding means and to permit light from the light source to pass through a perforation in a section of the tape at rest to a predetermined one of the keys of the typewriter, electromagnetic means for operating said key, a photocell carried by the key so as to receive the light directed on said key, and means controlled by the photocell to eiect energization of the electromagnetic means to' print the character represented by said perforation in the tape.

13. In a display device, a machine comprising a plurality of manipulative members, illuminating means, means for 'directing light from said illuminating means to said members in predetermined sequence, a light sensitive cell embedded in the head of each of said members, and means controlled by the light sensitive cells for operating the manipulative members in the same sequence and at substantially the same time as the light is received by the keys, whereby the keys of the typewriter on display appear to be operated directly by the light directed on said keys.

14. In a device of the class described, a keyboard having a pluralityrof keys, individual electromagnets for operating said keys, normally open circuit connections, one for each of said magnets, illuminating means, means to project light from th'e illuminating means upon the keys in a predetermined sequence, a distributor for selectively closing the 'circuit connections for operation of the magnets in corresponding sequence, a light sensitive cell carried by each key, and relay means controlled by said cell as the light is projected on the keys for completing the magnet circuits as said circuits are selected by the distributor.

15. In combination, a typewriter key, a solenoid for controlling the actuation of said key, a normally incomplete circuit connection for energizing said solenoid, a light responsive cell mounted on said key, a light source, means for directing light from the source on the cell, and means controlled by the cell when the light is directed thereon fo'r completing said circuit connection.

16. In combination, a typewriter keyboard comprising a plurality of keys, a plurality of solenoids, one for each key, for controlling the actuation of said keys, normally incomplete circuit connections for energizing said solenoids, light responsive cells carried by the keys, a light source, means for selectively directing the light from said source on the cells, and means controlled by each cell when the light is directed thereon for completing the circuit connection for its related solenoid.

17. In a device of the class described, a machine comprising a plurality of manipulative members each having an individual light responsive device thereon, a light source, means for directing a beam of light from said source upon selected light responsive devices individually in succession, and means controlled by said light responsive devices and adapted to operate in succession the manipulative members pertaining to the light responsive devices impinged upon by the beam of light.

THOMAS J. WATSON. 

